Novel compounds and syntheses



United States PatentO 3,076,820 NOVEL COMPOUNDS AND SYNTHESES Ethan ll. Blout, Belmont, Milton Green, Newton Highlands, Howard G. Rogers, Weston, and Myron S.

Simon, Newton Center, Mass., assignors to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware No Drawing. Filed Mar. 16, 1959, Ser. No. 799,427

3 Claims. (Cl. 260-377) This invention relates to photography and more particularly to products, compositions and processes for the development of photo-sensitive silver halide elements.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which colored developing agents are used to develop a latent image.

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel developing agent is capable of developing a latent image and imparting a reversed or positive colored image of said latent image to a superposed imagereceiving material.

Still another object is to provide novel products, processes and compositions suitable for use in preparing mono- .chromatic and multichromatic photographic images.

' volving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products and compositions possessing the. features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

The novel photographic developing agents employed in this invention possess the properties of both dye and a developing agent; thus they may be referred to as dye developers. The nature of these dye developers will be described hereinafter.

The photographic processes and compositions disclosed herein are particularly useful in the treatment of a latent image present in a photosensitive element, such as an exposed silver halide emulsion, whereby a positive dye image thereof maybe imparted to another element, herein referred to as an image-carrying or image-receiving element.

US. Patent No. 2,983,606, issued May 9, 1961, discloses. diffusion-transfer reversal processes wherein a photographic negative material such as a photographic element comprising an exposed silver halide emulsion layer containing a latent image, isprocessed to impart to an image-receiving element a reversed or positive dye image of said latent image by permeating into said emulsion layer a suitable liquid processing composition and bringing said emulsion layer into superposed relationship with an appropriate image-receiving layer. It is an object of this invention to provide additional dye developers suitable for use in such processes.

In carrying out the process of thisinvention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example, by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed, prior to, during or after wetting, on a sheetthis invention to apply the liquid processing composition prior to, exposure, in accordance with the disclosure in the copending application of Edwin H. Land, Serial No. 498,672, filed April 1, 1955. The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the latent image is developed, the oxidation product of the dye developer is immobilized or precipitated in exposed areas, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition. This immobilization is apparently, at least in part, due to a change in the solubility characteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. It may also be due, in part, to a tanning eiiect on the emulsion by the oxidized developing agent and to localized exhaustion of alkali due to development. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer or element, said transfer substantially excluding oxidized dye developer. Under certain circumstances, the layer of the liquid processing composition may be utilized as the image-receivinglayer. The latter element receives a depthwise diffusion, from the emulsion, of unoxidized dye developer without appreciably disturbing the imagewise distribution thereof to provide a reversed or positive, colored image of the developed image. The image-receiving element many contain agents adapted to mordant or otherwise fix the dufiused, nnoxidized dye developer. If the color of the diffused dye developer is affected by changes in the pH of the image-receiving element, this in temperature or other conditions. The desired positive image is revealed by stripping the image-receiving element from the photosensitive element at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example, in, on or behind the silver halide emulsion, or they may be utilized in the image-receiving element or in the liquid processing composition. In a preferred embodiment, a coating or layer of the dye developer is placed behind the silver halide emulsion, i.e., on the side of the emulsion adapted to be located most distant from the photographed subject when the emulsion is exposed and preferably also adapted to be most distant from the image-receiving element when in superposed relationship therewith. Placing the dye developer behind the emulsion layer, as in the preferred embodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any lightfiltering action by the colored dye developer. In this preferred embodiment, the layer of dye developer may be applied by using a coating solution containing about 0.5 to 8%, by weight, of the dye developer. Suitable concentrations may be used if the dye developer is utilized as a component of the liquid processing composition, concentrations as low as 0.2% in the liquid processing composition being suitable in certain instances.

The liquid processing composition above referred to comprises at least an aqueous solution of an alkaline compound, for example, diethylamine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may contain a conventional developing agent. It the liquid processing composition is to be applied to the emulsion by being spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosity-increasing compound constituting filmforming material of the type which, when said composileast one benzenoid developing group.

tion is spread and dried, will form a relatively firm and relatively stable film. A preferred film-forming material is a high molecular weight polymer such as a polymeric, Water-soluble ether inert to an alkali solution, as, for example, hydroxyethyl cellulose or sodium carhoxymethyl cellulose. Other film-forming materials or thickening agents whose ability to increase viscosity is substantially unaflected when left in solution for a long period of time may also be used.

The novel compounds of the present invention comprise anthraquinone dyes characterized in that they contain not less than one and preferably not more than four groups, more preferably not more than two groups, of the formula: (I) (H) 1?.

wherein Y and Y each of which may be the same or different, represent a divalent radical or a covalent bond; R represents hydrogen or a lower alkyl group; and Z represents a benzenoid developing group.

The preferred compounds of the present invention may be represented by the formula:

A nthraquinone-[Y- ON-Y1-Z] x wherein Y, R, Y and Z have the same significance as .noted in Formula I; and x is an integer from 1 to 4, in-

elusive.

In a preferred embodiment of Formula II, Z is p-dihydroxyphenyl group; Y is an ethylene group; Y is a covalent bond; R is hydrogen; and x is 2.

The term anthraquinone, as used herein, includes both unsubstituted and substituted anthraquinone nuclei. The anthraquinone nucleus may be substituted by various groups, such as hydroxyl; amino; aryl, e.g., phenyl;

etc.; and divalent organic radicals which contain both hetero and carbon atoms as constitutuent components,

as for example,

etc

The novel compounds of the present invention, as noted above, are anthraquinone dye developers which contain at As previously noted a preferred silver halide developing group comprises a para-dihydroxyphenyl group. Other suitable developing groups include ortho-dihydroxyphenyl and orthoand para-amino substituted hydroxyphenyl groups. In general, the developing group comprises a benzenoid developing configuration, that is, an aromatic developing group which forms quinonoid or quinone products upon oxidation. Preferred aromatic developing groups which form quinonoid or quinone oxidation products comprise aryl nuclei selected from the group consisting of benzene and naphthalene nuclei so substituted by at least two groups selected from the group consisting of hydroxyl and amino groups as to be capable of developing an exposed silver halide emulsion.

(III) R l Z-Y1N-H wherein Y and R have the same significance as previously noted; such as for example:

Amino-ethyl-hydroquinone, the preparation of which is disclosed in the copending U.S. application of Milton Green, Serial No. 514,095, filed June 8, 1955;

Amino-phenethyl-hydroquinone, the preparation of which is disclosed in US. Patent No. 3,019,107, issued Jan;- uary 30, 1962; I

Amino-phenethyl-thio-hydroquinone, the preparation of which is disclosed in US. Patent No. 3,009,958, issued November 21, 1961;

Amino-phenoxy-hydroquinone, the preparation of which is disclosed in the copending US. application of Milton Green and Warren E. Solodar, Serial No. 680,406, filed August 26, 1957;

Arnino-propyl-amino-hydroquinone, the preparation of which is disclosed in US. Patent No. 3,002,997, issued October 3, 1961;

Amino-hydroquinone, amino-phenyl-hydroquinone, and amino-phenyl-sulfonyl-hydroquinone, etc.; which may be prepared by known chemical reactions;

thraquinone carboXylic acid to the acid halide derivative 7 thereof, for example, to the acid chloride derivative thereof by reaction of said carboXylic group or groups with phosphorous trichloride (FCl phosphorous pentachloride (PCl or thionyl chloride(SOCl As examples of anthraquinone carboxylic acids suitable for use in the practice of the present invention, mention may be made of:

Anthraquinone-2-carboxylic acid; 1-chloroanthraquinone-2-carboxylic acid; 3-chloroanthraquinone-Z-carboxylic acid; 1-nitroanthraquinone-Z-carboxylic acid; 1-aminoanthraquinone-Z-carboxylic acid; Anthraquinone-l-carboxylic acid; Anthraquinone-Z,6-dicarboxylic acid; 1,S-dianilino-anthraquinone-2,6-dicarboxylic acid; 1,5-dibromo-anthraquinone-2,6-dicarboxylic acid; Anthraquinone-l,4-diaminopropionic acid; 3-aminoanthraquinone-Z-carboxylic acid; l-amino-4-bromo-anthraquinone-2-carboxylic acid; 1-amino-4-nitro-anthraquinone-2-carboxylic acid; 1,4-dihydroxyanthraquinone-Z-carboxylic acid; 1-nitroanthraquinone-Z-carboxylic acid; and l-anilino-anthraquinone-Z-carboxylic acid.

amassed Where an anthraquinone compound has groups other carboxyl groups which would react during the preparation of the acid chloride, suitable precautions should be taken to avoid undesired side reactions. Thus, where an anthraquinone compound has hydroxyl groups substituted other than on the anthraquinone ring, such groups may be acylated and the protective groups subsequently removed. It has been found that it is unnecessary to protect amino .or hydroxyl groups which are substituted in the tit-positions of the anthraquinone ring.

The invention will be illustrated in greater detail in conjunction with the following specific examples which set out a representative preparation and photographic utilization of the novel compounds of this invention, which, however, is not limited to the details therein set forth and is intended to be illustrative only.

Example I l,5-dianilino-anthraquinone-2,6-dicarboxylic acid (3 g.) is refluxed for about one and one-quarter hours in 25 cc. of thionyl chloride. The solution is then cooled and poured into 100cc. of dry benzene. A red solid precipitates and is filtered off and dried in vacuo to give 3 g. of the acid chloride. B-Aminoethylhydroquinone hydrobrornide (6 g.) in 50 cc. of absolute ethanol is treated with a solution of 1.4 g. of potassium hydroxide in 25 cc. of absolute ethanol. The precipitated salt is filtered and the alcohol removed under vacuum. The residual solid is dissolved in 60 cc. of pyridine. The acid chloride (2.45 g.) prepared above is added, and the solution refluxed under nitrogen for an hour. The reaction mixture is then poured onto ice, acidified with hydrochloric acid, and the solid filtered 01f. Crystallization from acetic acid gives 2.8 g. of a purple solid melting at approximately 210 C. Analysis of the product based on the structure I OH 1,5-bis anilino 2,6 bis 235' dihydroxyphenethylcarbamyl)-anthraquinone, gives a nitrogen value of 7.6% as compared to a calculated value of 7.5%.

Another dye developer within the scope of this invention 1,5-bis-anilino-2,6-bis-(2',5' dihydroxyphenylcarbamyl)- anthraquinone, which may be prepared using aminohydroquinone in a manner similar to that set forth in Example 1.

As an example of a suitable anthraquinone compound containing carboxyl groups which are attached to a bi- 6 valent organic radical Z rather than directly to the anthraquinone nucleus, mention may be made of:

with respect to each other, by hydroxyl groups, i.e., Z is a hydroquinonyl group, this is intended to be illustrative only. Thus, as previously noted, a silver halide developing function may be imparted to a benzene or naphthalene nucleus by hydroxyl, amino and/or substituted amino groups substituted in the ortho or para positions with respect to each other. It is to be noted also that Z may contain substituents other than those which supply the silver halide developing function so long as such substituents do not destroy the silver halide developing ability; such substituents include alkyl, hydroxyl, amino, halogen, etc. Reference is made to The Theory of the Photographic .Process, C. E. K. Mees (1st Ed., 1942), The Macmillan Co., New York, N.Y., p. 342 et seq., for a discussion of the chemical constitution of silver halide developing groups.

Where the developing function possessed by Z is supplied by hydroxyl or amino groups, it may be desirable to protect these groups as by acylation, to avoid side reactions or oxidation. Such protective groups are removed, as by hydrolysis, prior to photographic use.

()ne example of a photographic use of the dye developers herein disclosed, and set forth by way of illustration only, is the following:

Example 2 A photosensitive element is prepared by coating a gelatin-coated film base with the following solution:

Dye developer prepared in Example 1 g 0.3 Cellulose acetate hydrogen phthalate g 0.4 Acetone cc 8 Methanol cc 2 After this coating has dried, a silver iodobromide emulsion is applied. The photosensitive element is exposed and brought into superposed relationship with an imagereceiving element as an aqueous liquid processing composition comprising:

Percent Sodium carboxymethyl cellulose 4.5 Metol 0.1 Sodium hydroxide 2.5

is spread between said elements. The image-receiving element comprises a cellulose acetate coated baryta paper which has been coated with a 6% aqueous polyvinyl alcohol solution. After an imbibition period of approximately one minute, the image-receiving element is separated and contains a bluish-magenta positive image of the photographed subject.

'It will be noted that the liquid processing composition may, and in the above examples does, contain at least one auxiliary or accelerating developer such as p-methylaminophenol (Metol); 2,4-diarninophenol (Amidol); benzylaminophenol; or a 3-pyrazolidone, such as l-phenyl-3-pyrazolidone (Phenidone). The preferred auxiliary developer is l-phenyl-3-pyrazolidone. This auxiliary deyepoler serves to accelerate and possibly initiate the action of the dye developer. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developer.

The dye developers of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black-and-white, monochromatic or toned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 1 to 2% of 'the dye developer, 1% sodium hydroxide, 2% sodium sulfite and .O5% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to designate photographic images wherein the silver is retained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this invention are self-sufficient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in wh'ch the color is produced by a coupling reaction involving the oxidized developing agent.

The dye developers of this invention are preferably selected with a view to their usefulness in color photography and, in particular, their ability to provide the desired subtractive colors, i.e., magenta, yellow or cyan.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable known opaque and transparent materials, it is possible to obtain either a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials or" the type containing two or more photosensitized elements associated with an appropriate number of image-receiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive colors being incorporated in the photosensitized elements or in the liquid processing compositions. Examples of such photographic materials are disclosed in U.S. Patent No. 2,647,049 to Edwin H. Land.

The inventive concepts herein set forth are also adaptable for the formation of colored images in accordance with the photographic products and processes described in US. Patent No. 2,968,554, issued January 17, 1961,

Y and also the copending application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956.

In the preceding portions of the specification the expression color has been frequently used. This expres sion is intended to include the use of a plurality of colors to obtain black, as well as the use of a single black dye developer.

This application is in part a continuation of our copending U.S. application, Serial No. 52l,874, filed July 13, 1955 (now abandoned).

Our copending U.S. application, Serial No. 799,426, filed concurrently herewith, claims the photographic utilization of the novel compounds of the present invention, especially in ditlusion-transfer reversal processes.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An anthraquinone dye, containing not more than one anthraquinone nucleus, characterized in that it contains, as nuclear substituents, not less than one and not more than two groups of the formula:

group, and covalent bonds; and Z is a para-dihydroxyphenyl group.

2. 1,5 bis anilino 2,6 bis (2,5' dihydroxyphenethylcarbarnyl)-anthraquinone.

3. 1,5 bis anilino 2,6 bis (2,5 dihydroxyphenylcarbamyl) -anthraquinone.

References Cited in the file of this patent UNITED STATES PATENTS Beard June 16, 1936 Krause et al. Sept. 26, 1939 

1. AN ANTHRAQUINONE DYE, CONTAINING NOT MORE THAN ONE ANTHRAQUINODE NUCLEUS, CHARACTERIZED IN THAT IT CONTAINS, AS NUCLEAR SUBSTITUENTS, NOT LESS THAN ONE AND NOT MORE THAN TWO GROUPS OF THE FORMULA: 